Improved transient hot-spot temperature calculation method of high voltage bushings

The thermal transient is extremely important when evaluating a high-voltage bushing for overload capability. In this paper, we evaluate the previous methods by others in the effort of calculating bushing thermal transient and introduce our improved direct simulation method using ATP. We verify the validity of our method by comparing the simulation and actual test results which shows both match very well. We also use the method to evaluate the bushing overload condition recommended in IEEE C57.19.100 and the result shows the recommendation is not applicable.